The aim of this study is to determine whether women receiving a gonadotropin-releasing hormone agonist (GnRH-a) during in vitro fertilization-embryo transfer have adequate pituitary desensitization to GnRH and also to determine whether serum E2 is a valid measure of this phenomenon. We are documenting in a very thorough way a specific effect of dexamethasone on pituitary function that has never in the past been reported in vivo while there are some soft data reporting such an effect in vitro, and are planning to publish shortly after the completion of the study. An abstract derived from this protocol was presented as an oral short presentation at the 4th International Congress "The Young Woman at the Rise of the 21st Century: Gynecological and Reproductive Issues in Health and in Disease", Athens Hilton Hotel, Athens, Greece, November 18-31, 1998. The name of the presentation is, "Glucocorticoids modulate GnRH-a suppressed pituitary gonadotrophs".